This invention relates to devices for dispensing fluids.
More particularly, the present invention relates to automated dispensing devices for automatically dispensing fluids, such as liquid soap and the like.
Devices for dispensing fluids are well known and have been used to dispense liquid soaps, cleaning fluids, and condiments for many years. While capable of dispensing any fluid, the present invention is primarily concerned with dispensing liquid soap, which will be the primary area of discussion.
Liquid soap is typically dispensed by the reciprocal translation of a plunger that pumps liquid soap from a source and ejects it from an aperture. These dispensers require manual manipulation of the plunger. Such manipulation serves as a vehicle for transmission of bacterial and viral contaminants to subsequent users.
There also exist pneumatically actuated and mechanically (motor/pump) actuated mechanisms for dispensing soap in response to a trigger signal. These devices require a relatively substantial amount of power, usually in the form of electrical power, to maintain the air or gas pressure necessary to operate the pneumatic dispenser or to operate a motor in a mechanical dispenser. Conventional electric power (120 volts AC) creates an electrical hazard in proximity to a washbasin, or the like, reducing the desirability of devices requiring large quantities of power.
A prior art automated fluid dispenser is disclosed in U.S. Pat. No. 6,206,241 B1, issued Mar. 27, 2001, that includes some of the basic features of the present invention. This prior art dispenser includes a pump mechanism actuated by a piston movable between a first position and a second position in which a fluid is dispensed. A conduit is coupled to the pump mechanism and couplable to a pressurized fluid source. A valve is carried by the conduit and is movable between an open position in which a pressurized fluid from the pressurized fluid source moves the piston to the second position, and a closed position stopping the pressurized fluid.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
Accordingly, it is an object of the present invention to provide a new and improved automatic fluid dispenser.
Another object of the invention is to provide an automatic fluid dispenser that is simpler to manufacture.
And another object of the invention is to provide an automatic fluid dispenser that includes fewer components.
Briefly, to achieve the desired objects of the instant invention in accordance with a preferred embodiment thereof, provided is an automatic fluid dispenser including a pump mechanism having a housing defining a pump chamber with a fluid inlet coupled to a fluid source and a fluid outlet. An inlet check valve is mounted in the fluid inlet of the pump chamber to allow fluid to flow only into the pump chamber from the fluid source, and an outlet check valve is mounted in the fluid outlet to allow fluid to flow only out of the pump chamber to the fluid outlet. The inlet check valve is normally biased into a closed position while the outlet check valve may be unbiased for simplification or to provide anti-drip charateristics. The housing also defines a pressurized fluid chamber.
A reciprocating element is positioned within the pressurized fluid chamber for reciprocating motion between a first position in which the pump chamber has a first volume and a second position in which the pump chamber has a second, smaller volume. In one embodiment the reciprocating element includes a resilient diaphragm that ensures fluid separation of the pump chamber and the pressurized fluid chamber. The reciprocating element is biased into the first position and in one embodiment the resilient diaphragm provides the bias. Movement of the reciprocating element from the first position to the second position causes fluid contained in the pump chamber to be dispensed and movement of the reciprocating element from the second position to the first position causes fluid to be drawn into the pump chamber from the fluid source.
A pressurized fluid conduit is couplable to a pressurized fluid source and is coupled to the pressurized fluid chamber to supply pressurized fluid to the reciprocating element for moving the reciprocating element from the first position to the second position. A valve is carried by the pressurized fluid conduit. The valve is movable between an open position in which a pressurized fluid from the pressurized fluid source moves the reciprocating element to the second position and a closed position stopping the pressurized fluid. A pressurized fluid bleed is coupled to the pressurized fluid chamber adjacent the reciprocating element for relieving pressure in the pressurized fluid chamber when the valve is in the closed position. Relieving the pressure allows the biasing element to return the reciprocating element to the first position, which draws additional fluid into the fluid chamber from the fluid source. A sensor is used to actuate the valve from the closed position to the open position, the valve being normally biased to the closed position.
Also, the new and improved automatic fluid dispenser can be used in a variety of modern appliances to automatically introduce a fluid (e.g., soap, cleaner, softener, etc.) into the appliance during a selected portion of the operating cycle.